Bridged metallocenes for olefin copolymerization

ABSTRACT

The invention is directed to bridged metallocene catalyst complexes that are sufficiently soluble in aliphatic solvents to be particularly suitable for solution olefin polymerization processes such that olefin copolymers can be prepared with high molecular weights and catalyst activities particularly at high polymerization reaction temperatures. More specifically, the invention particularly relates to a polymerization process for ethylene copolymers having a density of about 0.850 to about 0.940 comprising contacting, under solution polymerization conditions at a reaction temperature at or above 60° C. to 250° C., ethylene and one or more comonomers capable of insertion polymerization with a bridged metallocene catalyst complex derived from two ancillary ligands, each of which independently may be substituted or unsubstituted, wherein the ligands are bonded by a covalent bridge containing a substituted single Group 14 atom, the substitution on said Group 14 atom comprising aryl groups at least one of which contains a hydrocarbylsilyl substituent; and B) an activating cocatalyst.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is related to the earlier filed provisionalapplications no. 60/105329, filed Oct. 23, 1998 and No. 60/131,067 filedApr. 26, 1999.

TECHNICAL FIELD

[0002] This invention relates to aryl-substituted-bridge containingorganometallic catalyst compounds suitable for olefin polymerizationprocesses.

BACKGROUND ART

[0003] Olefin polymers comprising ethylene and at least one or moreα-olefin and optionally one or more diolefin make up a large segment ofpolyolefin polymers and will be addressed as “ethylene copolymers”herein. Such polymers range from crystalline polyethylene copolymerssuch as High Density Polyethylene with a density in excess of 0.94, toslightly crystalline polyethylene such as Linear Low DensityPolyethylene with a density between 0.915 to 0.94, to largely amorphouselastomers with a density down to 0.85 and a relatively high molecularweight and with a new area of semi-crystalline “plastomers” with adensity of between 0.915 and 0.86 and a moderate molecular weight. Inparticular, ethylene copolymer plastomers are now a well establishedclass of industrial polymers having a variety of uses associated withtheir unique properties, such as elastomeric properties and theirthermo-oxidative stability. Uses of the plastomers include generalthermoplastic olefins, films, wire and cable coatings, polymermodification, injection molding, foams, footwear, sheeting,functionalized polymers and components in adhesive and sealantcompounds.

[0004] Commercially prepared ethylene copolymers have been traditionallybeen made via Ziegler-Natta polymerization with catalyst systems largelybased on vanadium or titanium. Newer metallocene catalyst compounds havereceived attention due to their ease of larger monomer incorporation andpotential increases in polymerization activities. U.S. Pat. No.5,324,800 describes metallocenes having substituted and unsubstitutedcyclopentadienyl ligands which are suitable for producing high molecularweight olefin polymers, including linear, low density copolymers ofethylene with minor amounts of α-olefin.

[0005] The utility of bridged metallocene-based ionic catalysts inolefin polymerization is described in U.S. Pat. Nos. 5,408,017 and5,767,208, EP 0 612 768, and EP 0 612 769. Each addresses suitablebridged metallocene catalysts for high temperature processes for olefincopolymerization. Substituted single carbon, or methylene, bridginggroups for metallocenes suitable as olefin polymerization catalysts isdescribed in U.S. Pat. Nos. 4,892,851, 5,155,080 and 5,132,381.Isopropylidene, mono- and diaryl methylene groups are identified asparticularly suitable.

[0006] Olefin solution polymerization processes are generally conductedin aliphatic solvents that serve both to maintain reaction mediumtemperature profiles and solvate the polymer products prepared. However,aryl-group containing metallocenes, those having cyclopentadienylderivatives and other fused or pendant aryl-group substituents, are atbest sparingly soluble in such solvents and typically are introduced inaryl solvents such as toluene . Solution polymerization processes inaliphatic solvents thus can be contaminated with toluene that must beremoved to maintain process efficiencies and to accommodatehealth-related concerns for both industrial manufacturing processes andpolymer products from them. Alternatively, relatively insolublecatalysts can be introduced via slurry methods, but such methodsrequired specialized handling and pumping procedures that complicate andadd significant costs to industrial scale plant design and operation.Low solubility can also become disadvantageous should the processinvolve low temperature operation at some stage such as in typicaladiabatic processes run in areas subject to low ambients temperatures.Additionally, separating or counteracting the build up in the recyclesystem of special catalyst solvents may become another problem. At thesame time means of maintaining high molecular weights in olefin polymerswhile operating at economically preferable high polymerization reactiontemperatures and high polymer production rates is highly desirable. Itis therefore desirable to provide a metallocene catalyst which is activefor polyethylene polymerization particularly at elevated temperatureswhich nevertheless has increased solubility in aliphatic solvents.

BRIEF SUMMARY OF THE INVENTION

[0007] The invention thus addresses specifically substituted, bridgedmetallocene catalyst complexes comprising a solubilizing covalent bridgecomprising at least one hydrocarbylsilyl substitutent. It can bedescribed as a Group 4 organometallic compound comprising two ancillarymonanionic ligands, each of which independently may be substituted orunsubstituted, wherein the ligands are bonded by a covalent bridgecontaining a substituted single Group 14 atom, the substitution on saidGroup 14 atom comprising aryl groups at least one of which contains atleast one hydrocarbylsilyl substituent group sufficient to provideincreased solubility in aliphatic solvents. Additionally, the inventionrelates to solution polymerization processes for ethylene copolymershaving a density of about 0.850 to about 0.940 comprising contacting,under supercritical or solution polymerization conditions at reactiontemperatures of 40° C. to 300° C., ethylene and one or more comonomerscapable of insertion polymerization with a metallocene catalyst complexderived from A) a metallocene compound having a covalent bridgeconnecting a cyclopentadienyl ligand to another ancillary anionic metalligand group, said bridge containing a substituted single Group 14 atom,the substitution on said Group 14 comprising aryl groups at least one ofwhich contains at least one hydrocarbylsilyl substituent group of theformula R² _(n)SiR¹ _(3-n), where each R¹ is independently a C₁-C₂₀hydrocarbyl, hydrocarbylsilyl, hydrofluorocarbyl substitutent, R² is aC₁-C₁₀ linking group between Si and the aryl group, and n=0, 1 or 2.Where n=0, the Si atom is covalently bound directly to an aryl groupring carbon atom.

DETAILED DESCRIPTION OF THE INVENTION

[0008] The bridged metallocene compounds of the invention are thosehaving a single substituted carbon or silicon atom bridging twoancillary monanionic ligands, such as substituted or unsubstitutedcyclopentadienyl-containing (Cp) ligands and/or substituted andunsubstituted Group 13-16 heteroatom ligands, of the metallocene metalcenters. The bridge substituents are substituted aryl groups, thesubstituents including at least one solubilizing hydrocarbylsilylsubstituent located on at least one of the aryl group bridgesubstituents. Substituents present on the cyclopentadienyl and/orheteroatom ligands include C₁-C₃₀ hydrocarbyl, hydrocarbylsilyl orhydrofluorocarbyl groups as replacements for one or more of the hydrogengroups on those ligands, or those on fused aromatic rings on thecyclopentadienyl rings. Aromatic rings can be substituents oncyclopentadienyl ligand and are inclusive of the indenyl and fluorenylderivatives of cyclopentadienyl groups, and their hydrogenatedcounterparts. Such typically may include one or more aromatic ringsubstituent selected from linear, branched, cyclic, aliphatic, aromaticor combined structure groups, including fused-ring or pendantconfigurations. Examples include methyl, isopropyl, n-propyl, n-butyl,isobutyl, tertiary butyl, neopentyl, phenyl, n-hexyl, cyclohexyl,benzyl, and adamantyl. For the purposes of this application the term“hydrocarbon” or “hydrocarbyl” is meant to include those compounds orgroups that have essentially hydrocarbon characteristics but optionallycontain not more than about 10 mol. % non-carbon heteroatoms, such asboron, silicon, oxygen, nitrogen, sulfur and phosphorous. Additionally,the term is meant to include hydrofluorocarbyl substitutent groups.“Hydrocarbylsilyl” is exemplified by, but not limited to, dihydrocarbyl-and trihydrocarbylsilyls, where the preferred hydrocarbyl groups arepreferably C₁-C₃₀ substituent hydrocarbyl, hydrocarbylsilyl orhydrofluorocarbyl substitutents for the bridging group phenyls. Forheteroatom containing catalysts see WO 92/00333. Also, the use ofhetero-atom containing rings or fused rings, where a non-carbon Group13, 14, 15 or 16 atom replaces one of the ring carbons is considered forthis specification to be within the terms “cyclopentadienyl”, “indenyl”,and “fluorenyl”. See, for example, the background and teachings of WO98/37106, having common priority with U.S. Ser. No. 08/999,214, filedDec. 29, 1997, and WO 98/41530, having common priority with U.S. Ser.No. 09/042,378, filed Mar. 13, 1998, both incorporated by reference forpurposes of U.S. patent practice.

[0009] These compounds can be generically represented as illustratedbelow:

[0010] where Cp is a substituted or unsubstitutedcyclopentadienyl-containing ancillary ligand, L is independentlyselected from Cp ligands as previously defined, or is a substituted orunsubstituted Group 13-16 heteroatom ligand, T is a Group 14element-containing bridging group, Ar¹ and Ar² are the substituted arylgroups which may be the same or different, M is a Group 3-6 metal, andX¹ and X² are the same or different labile ligands capable of beingabstracted for activation and suitable for olefin insertion, or capableof alkylation so as to be abstractable and suitable for olefininsertion. The term “ancillary ligand” is being used to refer to bulkymonoanioic ligands that stabilize the metal center to which bondedagainst oxidative reaction (i.e., debonding of the ligand by chemicalreaction) and the term “labile ligand” refers to ligands which may bereadily replaced, abstracted, or removed from the metal center to whichbonded.

[0011] For illustration purposes Ar¹ and Ar² may be independentlyselected from the groups below:

[0012] where any R′ is independently any of the groups below except Hand any R′″ is independently any of the groups below: H CH(CH₃)₂ C₄H₇CH₂CH═CH₂ CH₃ CH₂CH(CH₃)₂ C₅H₉ CH₂CH₂CH═CH₂ CH₂CH₃ CH₂CH₂CH(CH₃)₂ C₆H₁₁CH₂CH₂(CF₂)₇CF₃ CH₂CH₂CH₃ C(CH₃)₂CH(CH₃)₂ C₇H₁₃ CF₃ CH₂(CH₂)₂CH₃CH(C(CH₃)₃)CH(CH₃)₂ C₈H₁₅ N(CH₃)₂ CH₂(CH₂)₃₋₃₀CH₃ C(CH₃)₃ C₉H₁₇ N(C₂H₅)₂CH₂C(CH₃)₃ CH₂Si(CH₃)₃ C₆H₅ OC(CH₃)₃ CH═CH₂ CH₂Ph CH₂SiR₃

[0013] Cp and L, independently, may be any of ligands below where R′″ isas shown above.

[0014] X¹ and X² may independently be any of the groups listed for R′″plus any of Cl, Br, I, —NHR′″, —N(R′″)₂, or —OR′″. X¹ and X² mayadditionally be linked together so as to form a bidentate ligand such ascycloaliphatic hydrocarbyl bidentate ligand or cycloalkenyl hydrocarbylligand.

[0015] An illustrative representative is

[0016] where Me is methyl, Et is ethyl and Octyl is octyl.

[0017] Specific exemplary bridged hafnium catalysts include thosederived from: indenyl-based complexes such as the isomers, or mixtures,of di(para-triethylsilyl-phenyl) methylene bis(indenyl) hafniumdimethyl, di(para-trimethylsilyl-phenyl) methylene bis(indenyl) hafniumdimethyl, of di(para-tri-n-propylsilyl-phenyl) methylene bis(indenyl)hafnium dimethyl, (para-triethylsilyl-phenyl)(para-t-butylphenyl)methylene (fluorenyl) (indenyl) hafnium dimethyl,(para-triethylsilyl-phenyl) (para-methylphenyl)methylene (fluorenyl)(indenyl) hafnium dimethyl, di(para-triethylsilyl-phenyl) methylene(2,7-di tertbutyl fluorenyl) (indenyl) hafnium dimethyl,(para-trimethylsilyl-phenyl) (para-n-butylphenyl) methylene (2,7-ditertbutyl fluorenyl) (indenyl) hafnium dimethyl,(para-triethylsilyl-phenyl) (para-n-butylphenyl) methylenebis(tetrahydroindenyl) hafnium dibenzyl anddi(para-triethylsilyl-phenyl) methylene bis(tetrahydroindenyl) hafniumdimethyl.

[0018] Similarly, exemplary zirconium compounds includedi(para-triethylsilyl-phenyl) methylene bis(indenyl) zirconium dimethyl,di(para-trimethylsilyl-phenyl) methylene bis(indenyl) zirconiumdimethyl, of di(para-tri-n-propylsilyl-phenyl) methylene bis(indenyl)zirconium dimethyl, (para-triethylsilyl-phenyl)(para-t-butylphenyl)methylene (fluorenyl) (indenyl) zirconium dimethyl,(para-triethylsilyl-phenyl) (para-methylphenyl)methylene (fluorenyl)(indenyl) zirconium dimethyl, di(para-triethylsilyl-phenyl) methylene(2,7-di tertbutyl fluorenyl) (indenyl) zirconium dimethyl,(para-trimethylsilyl-phenyl) (para-n-butylphenyl) methylene (2,7-ditertbutyl fluorenyl) (indenyl) zirconium dimethyl,(para-triethylsilyl-phenyl) (para-n-butylphenyl) methylenebis(tetrahydroindenyl) zirconium dibenzyl anddi(para-triethylsilyl-phenyl) methylene bis(tetrahydroindenyl) zirconiumdimethyl. Additional preferred zirconium metallocenes useful whenprepared with the solubilizing bridging groups in accordance with thisinvention are those described in copending U.S. application Ser. No.09/251,819, filed Feb. 17, 1999, and equivalent WO 99/41294, thesecatalyst structures and the solution polymerization process describedwith them are particularly suited for this invention, and areincorporated by reference for purposes of U.S. patent practice.

[0019] Particularly suitable cyclopentadienyl-based complexes are thecompounds, isomers, or mixtures, of(para-trimethylsilylphenyl)(para-n-butylphenyl)methylene (fluorenyl)(cyclopentadienyl) hafnium dimethyl,di(para-trimethylsilylphenyl)methylene (2,7-di-tertbutyl fluorenyl)(cyclopentadienyl) hafnium dimethyl,di(para-triethylsilylphenyl)methylene (2,7-di-tertbutyl-fluorenyl)(cyclopentadienyl) hafnium dimethyl, (para-triethylsilylphenyl)(para-t-butylphenyl) methylene (2,7-di tertbutyl fluorenyl)(cyclopentadienyl) hafnium dimethyl or dibenzyl, anddi(para-triethylsilyl-phenyl)methylene(2,7-dimethylfluorenyl)(cyclopentadienyl) hafnium dimethyl or dibenzyl.The zirconocene analogues are(para-trimethylsilylphenyl)(para-n-butylphenyl)methylene (fluorenyl)(cyclopentadienyl) zirconium dimethyl,di(para-trimethylsilylphenyl)methylene (2,7-di-tertbutyl fluorenyl)(cyclopentadienyl) zirconium dimethyl,di(para-triethylsilylphenyl)methylene (2,7-di-tertbutyl-fluorenyl)(cyclopentadienyl) zirconium dimethyl, (para-triethylsilylphenyl)(para-t-butylphenyl) methylene (2,7-di tertbutyl fluorenyl)(cyclopentadienyl) zirconium dimethyl or dibenzyl, anddi(para-triethylsilyl-phenyl)methylene(2,7-dimethylfluorenyl)(cyclopentadienyl) zirconium dimethyl ordibenzyl. It has been found that the substituted bridge-containingcompounds, such as those asymmetric compounds listed above, areparticularly useful in accordance with the invention.

[0020] In particular, for the bridged metallocene compounds, increasingthe degree of substitution on an aromatic fused-ring substituted ligandCp can be effective for increased molecular weight, e.g.,2,7-dimethyl-fluorenyl, 2,7-di-tert-butyl-fluorenyl and2,7-methyl-phenyl-fluorenyl groups are exemplary of such. Preferablysubstitution on fluorenyl or indenyl radicals (ii) in the metallocenecompounds will generally comprise two or more C₁ to C₃₀ hydrocarbyl orhydrocarbylsilyl replacements, or substitutions, for a ring hydrogen ofat least one 6-member fused-ring, preferably both where a fluorenylradical.

[0021] The bridged metallocene compounds according to the invention maybe activated for polymerization catalysis in any manner sufficient toallow coordination or cationic polymerization. This can be achieved forcoordination polymerization when one ligand can be abstracted andanother will either allow insertion of the unsaturated monomers or willbe similarly abstractable for replacement with a ligand that allowsinsertion of the unsaturated monomer (labile ligands), e.g., alkyl,silyl, or hydride. The traditional activators of coordinationpolymerization art are suitable, those typically include Lewis acidssuch as alumoxane compounds, and ionizing, anion precursor compoundsthat abstract one so as to ionize the bridged metallocene metal centerinto a cation and provide a counter-balancing noncoordinating anion.

[0022] Alkylalumoxanes and modified alkylalumoxanes are suitable ascatalyst activators, particularly for the invention metal compoundscomprising halide ligands. The alumoxane component useful as catalystactivator typically is an oligomeric aluminum compound represented bythe general formula (R″—-Al—O)_(n), which is a cyclic compound, orR″(R″—Al—O)_(n)AlR″₂, which is a linear compound. In the generalalumoxane formula R″ is independently a C₁ to C₁₀ alkyl radical, forexample, methyl, ethyl, propyl, butyl or pentyl and “n” is an integerfrom 1 to about 50. Most preferably, R″ is methyl and “n” is at least 4.Alumoxanes can be prepared by various procedures known in the art. Forexample, an aluminum alkyl may be treated with water dissolved in aninert organic solvent, or it may be contacted with a hydrated salt, suchas hydrated copper sulfate suspended in an inert organic solvent, toyield an alumoxane. Generally, however prepared, the reaction of analuminum alkyl with a limited amount of water yields a mixture of thelinear and cyclic species of the alumoxane. Methylalumoxane and modifiedmethylalumoxanes are preferred. For further descriptions see, U.S. Pat.Nos. 4,665,208, 4,952,540, 5,041,584, 5,091,352, 5,206,199, 5,204,419,4,874,734, 4,924,018, 4,908,463, 4,968,827, 5,329,032, 5,248,801,5,235,081, 5,157,137, 5,103,031 and EP 0 561 476 A1, EP 0 279 586 B1, EP0 516 476 A, EP 0 594 218 A1 and WO 94/10180, each being incorporated byreference for purposes of U.S. patent practice.

[0023] When the activator is an alumoxane, the preferred transitionmetal compound to activator molar ratio is from 1:2000 to 10:1, morepreferably from about 1:500 to 10:1, even more preferably from about1:250 to 1:1 and most preferably from about 1:100 to 1:1.

[0024] The term “noncoordinating anion” is recognized to mean an anionwhich either does not coordinate to the metal cation or which is onlyweakly coordinated to it thereby remaining sufficiently labile to bedisplaced by a neutral Lewis base, such as an olefinically oracetylenically unsaturated monomer. Any complex capable ofcounterbalancing a cationic charge without impeding or interfering witholefin polymerization, including both being incapable of reacting withmetallocene cations so as to render them neutral and remainingsufficiently labile so as to be replaceable at the polymerization siteby olefin monomers, will be suitable in accordance with the invention.Typically such complexes are based on ionic salts or neutral Lewis acidsof the Group 8-14 metalloid or metal elements, particularly boron oraluminum having substituted aryl groups that are substituted so as topresent steric or electronic impediments to oxidation of the complexesby reaction of the transition metal center with the aryl groups bondedto the Group 13 atoms. Zwitterionic complexes of Group 13 elementscomprising both catonic and anionic charges where meeting the functionalrequisites above are additionally suitable.

[0025] Additional suitable anions are known in the art and will besuitable for use with the metallocene catalysts of the invention. See inparticular, U.S. Pat. No. 5,278,119 and the review articles by S. H.Strauss, “The Search for Larger and More Weakly Coordinating Anions”,Chem. Rev., 93, 927-942 (1993) and C. A. Reed, “Carboranes: A New Classof Weakly Coordinating Anions for Strong Electrophiles, Oxidants andSuperacids”, Acc. Chem. Res., 31, 133 -139 (1998).

[0026] Specific descriptions of ionic catalysts, those comprising atransition metal cation and a noncoordinating anion, suitable forcoordination polymerization appear in the U.S. Pat. Nos. 5,064,802,5,132,380, 5,198,401, 5,278,119, 5,321,106, 5,347,024, 5,408,017,5,599,671, and international publications WO 92/00333, WO 93/14132 andWO 97/35893. These teach a preferred method of preparation whereinmetallocenes are protonated by noncoordinating anion precursors suchthat an alkyl, alkenyl or hydride group is abstracted by protonationfrom a transition metal to make it both cationic and charge-balanced bythe noncoordinating anion.

[0027] The use of ionizing ionic compounds not containing an activeproton but capable of producing both the metallocene cation and annoncoordinating anion is also useful. See, EP-A-0 426 637, EP-A-0 573403 and U.S. Pat. No. 5,387,568 for instructive ionic compounds.Reactive cations of the ionizing ionic compounds, other than theBronsted acids, include ferrocenium, silver, tropylium,triphenylcarbenium and triethylsilylium, or alkali metal or alkalineearth metal cations such as sodium, magnesium or lithium cations. Afurther class of noncoordinating anion precursors suitable in accordancewith this invention are hydrated salts comprising the alkali metal oralkaline earth metal cations and a non-coordinating anion as describedabove. The hydrated salts can be prepared by reaction of the metalcation-noncoordinating anion salt with water, for example, by hydrolysisof the commercially available or readily synthesized LiB(pfp)₄ whichyields [Li·xH₂O] [B(pfp)₄], where (pfp) is pentafluorophenyl orperfluorophenyl.

[0028] Any metal or metalloid capable of forming a coordination complexwhich is resistant to degradation by water (or other Bronsted or LewisAcids) may be used or contained in the noncoordinating anion. Suitablemetals include, but are not limited to, aluminum, gold, platinum and thelike. Suitable metalloids include, but are not limited to, boron,phosphorus, silicon and the like. The description of noncoordinatinganions and precursors thereto of the documents of the foregoingparagraphs are incorporated by reference for purposes of U.S. patentpractice.

[0029] An additional method of making the active polymerizationcatalysts of this invention uses ionizing anion pre-cursors which areinitially neutral Lewis acids but form a metallocene cation and thenoncoordinating anion upon ionizing reaction with the inventioncompounds, for example tris(pentafluorophenyl) boron acts to abstract ahydrocarbyl, hydride or silyl ligand to yield a metallocene cation andstabilizing noncoordinating anion, see EP-A-0 427 697 and EP-A-0 520 732for illustration. See also the methods and compounds of EP-A-0 495 375.The description of noncoordinating anions and precursors thereto ofthese documents are similarly incorporated by reference for purposes ofU.S. patent practice.

[0030] When the X₁ and X₂ labile ligands are not hydride, hydrocarbyl orsilylhydrocarbyl, such as chloride, amido or alkoxy ligands and are notcapable of discrete ionizing abstraction with the ionizing, anionpre-cursor compounds, these X ligands can be converted via knownalkylation reactions with organometallic compounds such as lithium oraluminum hydrides or alkyls, alkylalumoxanes, Grignard reagents, etc.See EP-A-0 500 944, EP-A1-0 570 982 and EP-A1-0 612 768 for analogousprocesses describing the reaction of alkyl aluminum compounds withdihalide substituted metallocene compounds prior to or with the additionof activating noncoordinating anion precursor compounds.

[0031] Preferred invention activating cocatalyst, precursor ionizingcompounds comprise Group 13 element complexes having at least twohalogenated aromatic ligands such as the halogenated tetraphenyl boronand aluminum compounds exemplified in the identified prior art.Preferred aromatic ligands consist of the readily available phenyl, andpolycyclic aromatic hydrocarbons and aromatic ring assemblies in whichtwo or more rings (or fused ring systems) are joined directly to oneanother or together. These ligands, which may be the same or different,are covalently bonded directly to the metal/metalloid center. In apreferred embodiment the aryl groups are halogenated, preferablyfluorinated, tetraaryl Group 13 element anionic complexes comprising atleast one fused polycyclic aromatic hydrocarbon or pendant aromaticring. The halogenated ligands are also represented by those aryl ligandshaving flourinated alkyl groups. Indenyl, napthyl, anthracyl, heptalenyland biphenyl ligands are exemplary aryl ligands. See co-pendingapplication U.S. Ser. No. 09/261,627, filed Mar. 3, 1999, and equivalentWO 99/45042, incorporated by reference for the purposes of U.S. patentpractice.

[0032] Particularly preferred cocatalyst complexes for solutionpolymerization processes are those which are soluble in aliphaticsolvents, whether by virtue of substitution on the Group 13 elementligands or substitution on precursor cations, see for example U.S. Pat.No. 5,502,017 and WO 97/35893. When the cation portion of an ionicnoncoordinating anion precursor is a Bronsted acid such as protons orprotonated Lewis bases (excluding water), or a reducible Lewis acid suchas ferrocenium or silver cations, or alkaline metal or alkaline earthmetal cations such as those of sodium, magnesium or lithium cations, thetransition metal to activator molar ratio may be any ratio, butpreferably from about 10:1 to 1:10, more preferably from about 5:1 to1:5, even more preferably from about 2:1 to 1:2 and most preferably fromabout 1.2:1 to 1:1.2 with the ratio of about 1:1 being the mostpreferred.

[0033] Thus suitable active catalyst complexes for coordination andcarbocationic polymerization can be prepared by activation with thetraditional metallocene activators, typically alkylalumoxanes andionizing haloaryl boron or aluminum compounds known in the art. Theactive catalysts thus are catalytically active components comprisingcomplexes derived from the invention metallocene compounds containingthe solubilizing bridge binding together the ancillary ligands accordingto the invention, and activating cocatalyst compounds.

[0034] The catalyst complexes of the invention are useful inpolymerization of unsaturated monomers conventionally known to bepolymerizable under either coordination polymerization conditions orcationic polymerization conditions. Such conditions are well known andinclude solution polymerization, supercritical phase polymerization,slurry polymerization, and low, medium and high pressure gas-phasepolymerization. The catalyst of the invention may be supported and assuch will be particularly useful in the known operating modes employingfixed-bed, moving-bed, fluid-bed, or slurry processes conducted insingle, series or parallel reactors, with the added benefit thatincreased solubility will be useful in catalyst synthesis processeswhere the introduction of toluene is to be reduced. or slurry pumpintroduction means to be avoided.

[0035] When using the catalysts of the invention, the total catalystsystem will generally additionally comprise one or more organometalliccompound. Such compounds as used in this application and its claims ismeant to include those compounds effective for removing polar impuritiesfrom the reaction environment and for increasing catalyst activity.Impurities can be inadvertently introduced with any of thepolymerization reaction components, particularly with solvent, monomerand catalyst feed, and adversely affect catalyst activity and stability.It can result in decreasing or even elimination of catalytic activity,particularly when ionizing anion pre-cursors activate the catalystsystem. The polar impurities, or catalyst poisons include water, oxygen,metal impurities, etc. Preferably steps are taken before provision ofsuch into the reaction vessel, for example by chemical treatment orcareful separation techniques after or during the synthesis orpreparation of the various components, but some minor amounts oforganometallic compound will still normally be used in thepolymerization process itself.

[0036] Typically these compounds will be organometallic compounds suchas the Group 13 organometallic compounds of U.S. Pat. Nos. 5,153,157,5,241,025 and WO-A-91/09882, WO-A-94/03506, WO-A-93/14132, and that ofWO 95/07941. Exemplary compounds include triethyl aluminum, triethylborane, triisobutyl aluminum, methylalumoxane, and isobutylaluminumoxane. Those compounds having bulky or C₆-C₂₀ linear hydrocarbylsubstituents covalently bound to the metal or metalloid center beingpreferred to minimize adverse interaction with the active catalyst.Examples include triethylaluminum, but more preferably, bulky compoundssuch as triisobutylaluminum, trisoprenylaluminum, and long-chain linearalkyl-substituted aluminum compounds, such as tri-n-hexylaluminum,tri-n-octylaluminum, or tri-n-dodecylaluminum. When alumoxane is used asactivator, any excess over the amount needed to activate the catalystspresent can act as a poison scavenger compound and additionalorganometallic compounds may not be necessary. Alumoxanes also may beused in scavenging amounts with other means of activation, e.g.,methylalumoxane and trisobutyl-aluminoxane with boron-based activators.The amount of such compounds to be used with catalyst compounds of theinventions is minimized during polymerization reactions to that amounteffective to enhance activity (and with that amount necessary foractivation of the catalyst compounds if used in a dual role) sinceexcess amounts may act as catalyst poisons.

[0037] In preferred embodiments of the process for this invention, thecatalyst system is employed in liquid phase (solution, slurry,suspension, bulk phase or combinations thereof), in high pressure liquidor supercritical fluid phase. Each of these processes may be employed insingular, parallel or series reactors. The liquid processes comprisecontacting olefin monomers with the above described catalyst system in asuitable diluent or solvent and allowing said monomers to react for asufficient time to produce the invention copolymers. Aliphatic solventsand mixed aliphatic solvents are industrially suitable for solutionprocesses, and are particularly preferred.

[0038] The process of the invention is especially applicable tohomogeneous solution polymerization which is also substantiallyadiabatic, that is to say the heat of polymerization is accommodated bya rise in temperature of the polymerization reactor contents, hereprincipally solvent. This adiabatic process typically has no internalcooling and suitably no external cooling. The reactor outlet streamremoves the heat of polymerization from the reactor. The productivity ofsuch adiabatic processes can be improved by cooling the inlet solventand/or monomer stream(s) prior to introduction into the reactor topermit a greater polymerization exotherm. Thus the catalyst, cocatalystand scavenger selections disclosed in this application can beadvantageously practiced in a continuous, solution process operated ator above 140° C., above 150° C. or above 160° C., up to about 250° C.Typically, this process is conducted in an inert hydrocarbon solvent,linear, cyclic or branched aliphatic, or aromatic, at a pressure of from20 to 200 bar. These catalysts' ability to provide a commerciallydesirable polymer at elevated temperatures contributes to a greaterexotherm, to high polymer contents in the reactor because of lowerviscosity, and to reduced energy consumption in evaporating andrecycling solvent, and better monomer and comonomer conversions. See,for example, U.S. Pat. No. 5,767,208, and co-pending U.S. applicationSer. No. 09/261,637, filed Mar. 3, 1999, and its equivalent WO 99/45041,all of which are incorporated by reference for purposes of U.S. patentpractice.

[0039] The catalyst according to the invention may be supported for usein gas phase, bulk, slurry polymerization processes, or otherwise asneeded. Numerous methods of support are known in the art forcopolymerization processes for olefins, any is suitable for theinvention process in its broadest scope. See, for example, alumoxaneactivated catalysts of U.S. Pat. Nos. 5,057,475 and 5,227,440. Anexample of supported ionic catalysts appears in WO 94/03056.Particularly effective methods for ionic catalysts are that described inU.S. Pat. Nos. 5,427,991, 5,647,847 and WO 98/55518. A bulk, or slurry,process utilizing supported, invention metallocene compounds activatedwith alumoxane co-catalysts can be utilized as described forethylene-propylene rubber in U.S. Pat. Nos. 5,001,205 and 5,229,478,these processes will additionally be suitable with the catalyst systemsof this application. Both inorganic oxide and polymeric supports may beutilized in accordance with the knowledge in the field. See U.S. Pat.Nos. 5,422,325, 5,427,991, 5,498,582, 5,466,649, copending U.S. patentapplication Ser. Nos. 08/265,532 and 08/265,533, both filed Jun. 24,1995, and international publications WO 93/11172 and WO 94/07928. Eachof the foregoing documents is incorporated by reference for purposes ofU.S. patent practice.

[0040] Bulk and slurry processes are typically done by contacting thecatalysts with a slurry of liquid monomer or diluent, the catalystsystem being supported. Gas phase processes typically use a supportedcatalyst and are conducted in any manner known to be suitable forethylene homopolymers or copolymers prepared by coordinationpolymerization. Illustrative examples may be found in U.S. Pat. Nos.4,543,399, 4,588,790, 5,028,670, 5,382,638, 5,352,749, 5,436,304,5,453,471, and 5,463,999, and WO 95/07942. Each is incorporated byreference for purposes of U.S. patent practice.

[0041] Generally speaking the polymerization reaction temperature canvary from about −50° C. to about 300° C. Preferably the reactiontemperature conditions will be from −20° C. to 250°, and mostadvantageously in high temperature, adiabatic solution processes fromand including about 120° C. to including and about 230° C. The pressurecan vary from about 1 mm Hg to 2500 bar, preferably from 0.1 bar to 1600bar, most preferably from 1.0 to 500 bar.

[0042] Ethylene-α-olefin (including ethylene-cyclic olefin andethylene-α-olefin-diolefin) elastomers of high molecular weight and lowcrystallinity can be prepared utilizing the catalysts of the inventionunder traditional solution polymerization processes (above) or byintroducing ethylene gas into a slurry utilizing the α-olefin or cyclicolefin or mixture thereof with other monomers, polymerizable and not, asa polymerization diluent in which the invention catalyst is suspended.Typical ethylene pressures will be between 10 and 1000 psig (69-6895kPa) and the polymerization diluent temperature will typically bebetween −10-160° C. The process can be carried out in a stirred tankreactor or tubular reactor, or more than one operated in series orparallel. See the general disclosure of U.S. Pat. No. 5,001,205 forgeneral process conditions. All documents are incorporated by referencefor description of polymerization processes, ionic activators and usefulscavenging compounds.

[0043] Pre-polymerization of the supported catalyst of the invention mayalso be used for further control of polymer particle morphology intypical slurry or gas phase reaction processes in accordance withconventional teachings. For example such can be accomplished bypre-polymerizing a C₂-C₆ alpha-olefin for a limited time, for example,ethylene is contacted with the supported catalyst at a temperature of−15 to 30° C. and ethylene pressure of up to about 250 psig (1724 kPa)for 75 min. to obtain a polymeric coating on the support of polyethyleneof 30,000-150,000 molecular weight. The pre-polymerized catalyst is thenavailable for use in the polymerization processes referred to above. Theuse of polymeric resins as a support coating may additionally beutilized, typically by suspending a solid support in dissolved resin ofsuch material as polystyrene with subsequent separation and drying. Alldocuments are incorporated by reference for description of metallocenecompounds, ionic activators and useful scavenging compounds.

[0044] Other olefinically unsaturated monomers besides thosespecifically described above may be polymerized using the catalystsaccording to the invention by coordination polymerization, for example,styrene, alkyl-substituted styrenes, ethylidene norbornene, vinylnorbornene, norbornadiene, dicyclopentadiene, and otherolefinically-unsaturated monomers, including other cyclic olefins, suchas cyclopentene, norbornene, and alkyl-substituted norbornenes.Additionally, alpha-olefinic macromonomers of up to 300 mer units, ormore, may also be incorporated by copolymerization.

[0045] The following examples are presented to illustrate the foregoingdiscussion. All parts, proportions and percentages are by weight unlessotherwise indicated. All examples were carried out in dry, oxygen-freeenvironments and solvents. Although the examples may be directed tocertain embodiments of the present invention, they are not to be viewedas limiting the invention in any specific respect. In these examplescertain abbreviations are used to facilitate the description. Theseinclude standard chemical abbreviations for the elements and certaincommonly accepted abbreviations, such as: Me=methyl, Et=ethyl,t-Bu=tertiary-butyl, Oct=octyl, Cp=cyclopentadienyl, Ind=indenyl,Flu=fluorenyl, THF (or thf)=tetrahydrofuran, Ph=phenyl, andpfp=pentafluorophenyl.

[0046] All molecular weights are weight average molecular weight unlessotherwise noted. Molecular weights (weight average molecular weight (Mw)and number average molecular weight (Mn) were measured by Gel PermeationChromatography, unless otherwise noted, using a Waters 150 GelPermeation Chromatograph equipped with a differential refractive index(DRI) and low angle light scattering (LS) detectors and calibrated usingpolystyrene standards. Samples were run in 1,2,4-trichlorobenzene (135°C.) using three Polymer Laboratories PC Gel mixed B columns in series.This general technique is discussed in “Liquid Chromatography ofPolymers and Related Materials III” J. Cazes Ed., Marcel Decker, 1981,page 207, which is incorporated by reference for purposes of U.S. patentpractice herein. No corrections for column spreading were employed;however, data on generally accepted standards, e.g. National Bureau ofStandards Polyethylene 1475, demonstrated a precision with 0.2 units forMw/Mn which was calculated from elution times.

EXAMPLES

[0047] Synthesis of (p-Et₃Si-phenyl)₂C(2,7-^(t)Bu₂Flu)(Cp)HfMe₂(Catalyst A)

[0048] 1. Synthesis of 1-Br,4-(Et₃Si)benzene

[0049] To a cold (−78° C.) slurry of 1,4-dibromobenzene (235 g, 0.99mol) and anhydrous THF (1.5 L) was added a solution of nBuLi (1.0 mol),pentane (300 mL) and ether (100 mL). After stirring for 3 h, Et₃SiCl(150 g, 1.0 mol) was added. The mixture was allowed to slowly warm toroom temperature, stirred for a total of ca. 60 h. then quenched withwater (50 mL). The organic layer was separated, washed with additionalwater (2×50 mL), dried over MgSO₄, filtered, then reduced to an orangeoil. Vacuum distillation (60 mtorr) gave product (bp 83° C.). Yield 124g, 46%.

[0050] 2. Synthesis of 6,6′-bis(p-Et₃Si-phenyl)fulvene

[0051] To a cold (−78° C.) slurry of 1-Br,4-(Et₃Si)benzene (124 g, 0.46mol) and anhydrous THF (0.5 L) was added a solution of nBuLi (0.46 mol)and pentane (246 mL). After stirring for 75 min, ClC(O)NMe₂ (21 mL, 0.23mol) was added. The mixture was slowly warmed to room temperatureovernight then cooled in an ice bath. Cyclopentadiene (46 mL, 0.55 mol)was added then the color soon turned red. After stirring in an ice bathfor 8 h, the mixture was warmed to room temperature overnight. Themixture was extracted with water (4×100 mL) in two stages (tot. 800 mLwater), dried with MgSO₄ then reduced to an oil. The oil was taken up inether (200 mL), dried with CaH₂, filtered, then reduced to a red oil.Yield of crude product 114.8 g.

[0052] 3. Synthesis of (p-Et₃Si-phenyl)₂C(2,7-^(t)Bu₂Flu)(Cp)HfCl₂.

[0053]2,7-^(t)Bu₂fluorenyl lithium (69.5 g, 0.25 mol) was added to acooled (−30° C.) solution of the crude fulvene (114.8 g, 0.25 mol) andether (500 mL). The mixture was warmed to room temperature overnightthen reduced to an orange oil. Addition of pentane (0.5 L) caused aslurry to form. Filtration, pentane washing (2×100 mL) and dryingyielded (p-Et₃Si-phenyl)₂C(2,7-^(t)Bu₂FluH)(CpLi) as a white solid (97g, 53%-assuming no ether present). 2M BuLi in pentane (64.5 mL, 0.129mol) was added to a slurry of the monoanion (95 g, 0.129 mol) and ether(1 L). After stirring overnight, the orange mixture was cooled to −30°C. then treated with HfCl₄ (41.4 g, 1 equiv.). The mixture was warmed toroom temperature, stirred for 24 h then reduced to a solid in vacuo. Thesolids were extracted with methylene chloride (500 mL total) thenfiltered through Celite. The filtrate was reduced to a solid, extractedwith pentane (3×100 mL) then dried. The product was extracted from thesolids with a mixture of toluene and hexane (1:1) at 60° C. thenfiltered through a 0.45 μm filter. Removing the solvent gave product.Yield 70 g, 55%.

[0054] 4. Synthesis of (p-Et₃Si-phenyl)₂C(2,7-^(t)Bu₂F u)(Cp)HfMe₂(Catalyst A)

[0055] A 1.4 M solution of MeLi in ether (21.8 mL, 30.5 mmol) was addedto a solution of (p-Et₃Si-phenyl)₂C(2,7-^(t)Bu₂Flu)(Cp)HfCl₂ (15.0 g,15.2 mmol) and toluene (125 mL). After stirring for 1 h, the mixture wasfiltered through a 4-8 μm frit then reduced to a solid invacuo. Theproduct was extracted from the solids with hexane (250 mL) then filteredthrough a 0.45 μm filter. The crude product was crystallized from aminimum of hot hexane. Yield 8.9 g, 62%.

[0056] Synthesis of (p-Et₃Si-phenyl)₂C(Flu)(Cp)HfMe₂ (Catalyst B)

[0057] 5. Synthesis of 6,6′-bis(p-Et₃Si-phenyl)fulvene

[0058] This fulvene was prepared similarly as described above in 1 and 2on a smaller scale.

[0059] 6. Synthesis of (p-Et₃Si-phenyl)₂C(Flu)(Cp)HfCl₂.

[0060] Fluorenyl lithium (3.90 g, 22.6 mmol) was added to a cold (−30°C.) solution of crude 6,6′-bis(p-Et₃Si-phenyl)fulvene (10.35 g, 22.6mmol) and ether (100 mL). After stirring for 2 h, the solvent wasremoved and the remaining solid slurried with pentane (100 mL),filtered, washed with additional pentane (2×100 mL) then dried invacuoto give (p-Et₃Si-phenyl)₂C(FluH)(CpLi). Yield 6.41 g, 45%-assuming noether present. 2M BuLi in pentane (5.1 mL, 1 equiv.) was added to aslurry of the monoanion (6.4 g, 10.2 mmol) and ether (50 mL). Themixture was stirred overnight, cooled to −30° C. then treated with HfCl₄(3.26 g, 1 equiv.). The mixture was warmed to room temperature, stirredfor 8 h, filtered then washed with pentane (25 mL). The product wasextracted from the orange solids with methylene chloride. Removing thesolvent gave (p-Et₃Si-phenyl)₂C(Flu)(Cp)HfCl₂. Yield 6.15 g, 61%.

[0061] 7. Synthesis of (p-Et₃Si-phenyl)₂C(Flu)(Cp)HfMe₂ (Catalyst B)

[0062] A 1.4 M solution of MeLi in ether (1.65 mL, 2.31 mmol) was addedto a solution of (p-Et₃Si-phenyl)₂C(Flu)(Cp)HfCl₂ (1.0 g, 1.15 mmol) andtoluene (25 mL). After stirring overnight, toluene was removed. Theproduct was extracted from the solids with hexane then filtered througha 0.45 μm filter. Removing the solvent gave product. Yield 0.565 g, 59%.

[0063] As shown above preparation of the exemplary metallocenes requiredinitial synthesis of 6,6′-bis(p-Et₃Si-phenyl)fulvene. This fulvene wasprepared from the reaction of p-(Et₃Si)phenyllithium with ClC(O)NMe₂then cyclopentadiene in an extension of a general procedure reported byH. Kurata and coworkers (Tetrahedron Letters, 1993, 34, 3445-3448).Further reaction of 6,6′-bis(p-Et₃Si-phenyl)fulvene with2,7-^(t)Bu₂fluorenyl lithium yielded(p-Et₃Si-phenyl)₂C(2,7-^(t)Bu2FluH)(CpLi). This monoanion displayed lowsolubility in pentane and was easily purified from contaminants.Subsequent treatment with BuLi then HfCl₄ gave the dichloride(p-Et₃Si-phenyl)₂C(Flu)(Cp)HfCl₂, which was readily methylated. Thismethodology can easily be extended to prepare a wide variety of silylsubstituted metallocenes.

[0064] 8. Solubility Studies

[0065] To a measured amount (typically 10⁻⁴ mol) of metallocene and astirbar in a 20 mL scintillation vial was added dry hexane (ca. 2.65mL). It was necessary to use a larger amount of A (3×10⁻⁴ mol) todetermine its solubility. The mixture was stirred for ca. 1 h then analiquot removed and filtered through a 0.45 μm filter (aliquot mass2.2-2.5 g). The mass of the sample was recorded then the hexane removedwith a slow nitrogen stream. Weight % solubility of the metallocene wasdetermined as 100 (mass solid remaining)/(mass filtered aliquot). SeeTables below. Catalyst Symbol Precatalyst Compound A(p-Et₃Si-Ph)₂C(2,7-(^(t)Bu)₂Flu)(Cp)HfMe₂ B (p-Et₃Si-Ph)₂C(Flu)(Cp)HfMe₂C (Comp) Ph₂C(2,7-(^(t)Bu)₂Flu)(Cp)HfMe₂ D (Comp) Ph₂C(Flu)(Cp)HfMe₂

[0066] SOLUBILITY TABLE Initial Mixture (Calculated) Filtered AliquotPrecatalyst Precat soln. mass max. wt % soln. mass Precat wt % A 0.09052.6603 3.40% 2.3715 0.0793 3.3%¹ A 0.2828 2.7653 10.23% 2.521 0.24349.65%³ A 0.2844 2.8224 10.08% 2.5557 0.2338 9.15%³ C (Comp) 0.07052.6191 2.69% 2.236 0.0476 2.1% C (Comp) 0.1049 2.6805 3.91% 2.383 0.04451.9% B 0.0848 2.6483 3.20% 2.3898 0.0511 2.1% D (Comp) 0.0594 5.10691.16% 3.7209 0.0045 0.1%² D (Comp) 0.0612 12.1902 0.50% 11.5233 0.0079<0.07%²

Example 9a Polymerization Example.

[0067] Under a nitrogen atmosphere, a 1 L autoclave was charged withhexane (460 mL) and trioctylaluminum (0.04 mL of a 25 wt % solution inhexane diluted with hexane (10 mL)). The autoclave was stirred at ca.1000 rpm, heated to 113.6±0.4° C. (P=47.2±0.5 psig) then pressurizedwith propylene to 103.3±0.3 psig then ethylene to 251 psig.

[0068] Ethylene flow into the reactor was allowed during thecopolymerization. A 3.94×10⁻⁵ M of hexane soluble activator[((3,5-(Et₃Si)₂-Ph)₃C]+[B(C₆F₅)₄]⁻ solution in hexane (20 mL, 0.79 μmol)(hexane soluble activator) was pumped into the reactor. Then a 3.97×10⁻⁵M (p-Et₃Si—Ph)₂C(2,7-^(t)BU₂Flu)(Cp)HfMe₂ solution in hexane was addedat a variable rate sufficient to maintain ethylene flow into the reactorat <1 L/min and the reaction exotherm <0.5° C. The mean temperatureduring the polymerizations was 113.7±0.5° C. Ethylene uptake wasmonitored with a calibrated mass-flow transducer. The polymerization washalted after ca. 12 g of polymer was produced. The reactor was ventedand cooled. The polymer solution was poured from the reactor into alarge beaker. The reactor was rinsed with additional hot hexane (ca. 500mL). The polymer solutions were combined then treated with a stream ofnitrogen to remove hexane; the polymer was further dried under vacuum at80° C. Polymerization data is given in table 1.

Example 9b

[0069] The procedure of 9a. was repeated.

Example 9c

[0070] The procedure of 9a. was repeated.

Example 10a

[0071] The general procedure of 9a. was followed with an activatorsubstitution: The reactor was charged with solvent, AlOct₃ then a slurryof the activator compound PhNMe₂H⁺B(C₆F₅)₄−(5 mg, 6.2 μmol) in hexane(20 mL) then heated to 113.5° C. and charged with propylene andethylene. Then the precatalyst was added to this mixture.

Example 10b

[0072] The procedure of 10a. was repeated using a slurry of theactivator compound [PhNMe₂H]⁺[B(C₆F₅)₄]⁻(1.2 mg, 1.5 μmol) in hexane (20mL).

Example 11a Comparative Example

[0073] The general procedure of 9a. was followed with an activatorsubstitution: A 1.5×10⁻⁴ M B(C₆F₅)₃ solution in hexane (25 mL, 3.78μmol) was pumped into the reactor in place of the R1 solution used inexample 9a. Due to low activity, the polymerization was halted after2.92 g of polymer was prepared.

Example 11b Comparative Example

[0074] The procedure of 11a. was repeated. Due to low activity, thepolymerization was halted after 0.7 g of polymer was prepared.

Example 12a Polymerization Example.

[0075] The procedure of example 9a was followed with a precatalystsubstitution: A mixture of (p-Et₃Si—Ph)₂C(Flu)(Cp)HfMe₂ (50 mg, 60.1μmol) and hexane (2.5 g) was stirred for 30 min then allowed to sit for10 min. An aliquot (150 μL) of the mixture was removed and diluted withhexane 80 mL. This precatalyst solution was added to a reactor asdescribed in example 9a.

Example 12b Polymerization Example

[0076] The procedure of example 12a was repeated using the sameprecursor.

Example 12c Comparative Example

[0077] The procedure of example 9a was followed with a precatalystsubstitution: A mixture of catalyst D above ((Ph)₂C(Flu)(Cp)HfMe₂) (50mg, 82.9 μmol) and hexane (2.5 g) was stirred for 30 min then allowed tosit for 10 min. An aliquot (150 μL) of the mixture was removed anddiluted with hexane 80 mL. This precatalyst solution was added to areactor as described in example 9a.

Example 12d Comparative Example

[0078] The procedure of example 12c was repeated using the same mixture.TABLE 1 POLYMERIZATION RESULTS Polymer Wt % C₃ M_(w) M_(w)/M_(n) Ex #μmol Cat μmol Act mass (IR) (LS) (DRI) 9a 0.13 0.79 12.41 32 629427 1.859b 0.11 0.79 11.79 31 647659 1.7 9c 0.12 0.79 10.33 32 575956 1.9 10a0.056 6.2 11.42 32 557884 1.95 10b 0.094 1.5 11.28 32.5 589690 1.911a(Comp) 0.70 3.8 2.92 32 573913 1.9 11b(Comp) 0.893 3.8 0.7 (a) (a)(a) 12a 0.183 (b) 0.79 12.60 31 510697 2.0 12b 0.183 (b) 0.79 6.77 33.5492952 2.0 12c(Comp) (c) 0.79 0.4 (a) (a) (a) 12d(Comp) (c) 0.79 0 (a)(a) (a)

[0079] The comparison presented in example 12 above illustrates that theproductivity of a polymerization is proportional to the concentration ofthe catalyst precursor compound feed solution. Catalyst B is moresoluble that catalyst D in hexane. Thus, the mixtures of B in hexaneresult in and increase in polymerization productivity, 6.8 to 12.6 gpolymer, as compared to that of catalyst D, at 0-0.4 g polymer.

Example 13 Ethylene/Octene Copolymerizations

[0080] Under a nitrogen atmosphere, a 500 mL autoclave was charged withhexane (250 mL), triisobutylaluminum (0.2 mL of a 25.2 wt % solution inheptane diluted with toluene (5 mL)) and 1-octene (18 mL, 115 mmol). Theautoclave was stirred at ca. 1500 rpm, heated to 140.1° C. (P=75.7 psig)then pressurized with ethylene to 265.6±1 psig. Ethylene flow into thereactor was allowed during the copolymerization. A solution ofprecatalyst (40-50 μmol), PhNMe ₂H⁺ B(C₆F₅)₄ ⁻ (1 equiv.) and toluene(100 mL) was added to the stirred mixture over 30 min. at a variablerate sufficient to obtain 12-15 g isolated copolymer with an exotherm ofless than 1.5° C., typically less than 1° C. The polymer wasprecipitated with 2-propanol (1.5 L), isolated, then dried under vacuumat 80° C. See Table below. Precat. used Copolymer Mol % M_(w)M_(w)/M_(n) M_(w) Precatalyst (μMol) Yield (g) octene (DRI) (DRI) (LS) A2.1 12.18 6.4 195692 3.12 225188 A 1.5 12.79 6.1 190771 2.30 210680 A2.2 13.82 6.4 207125 2.30 248319 A 2.4 14.98 6.1 219112 2.43 254290 B5.0 12.40 7.3 150225 2.22 177924 B 4.4 12.98 7.6 163758 2.22 194604 D5.8 12.49 9.5 140664 2.25 173690 D 4.2 12.25 7.5 154822 2.20 189865

[0081] The solubility data above exhibits significant and unexpectedincrease in solubility for catalyst of the invention as compared withthose of the prior art. The polymerization data illustrates equivalentactivities such that the benefits of increased solubility in aliphaticsolvents can be achieved without sacrifice of the levels of productivitypreviously achieved with the prior art catalysts.

Example 14 Continuous High Temperature Solution Process

[0082] The following polymerization reactions were performed in astirred, liquid filled 2 L jacketed steel reactor equipped to performcontinuous insertion polymerization in presence of an inert C₆hydrocarbon (naphta) solvent at pressures up to 120 bar and temperaturesup to 240° C. The reactor was typically stirred at 1000 rpm during thepolymerization. The reaction system was supplied with a thermocouple anda pressure transducer to monitor changes in temperature and pressurecontinuously, and with means to supply continuously purified ethylene,1-octene, and solvent. In this system, ethylene dissolved in thehydrocarbon solvent, 1-octene, tri-n-octyl aluminum (TOA) used as ascavenger, and optionally H₂, are pumped separately, mixed, and fed tothe reactor as a single stream, refrigerated to below 0° C. Thetransition metal component (TMC) was dissolved in a solvent/toluenemixture (9/1 vol/vol) whereas the non-coordinating anion (NCA) activatorwas dissolved in toluene/solvent mixture (1/1 vol/vol). Both componentswere pumped separately, mixed at ambient temperature, and cooled tobelow about 0° C. prior to entering the reactor. The reactor temperaturewas set by adjusting the temperature of an oil bath used as a reservoirfor the oil flowing through the reactor wall jacket. Next, the polymermolecular weight (MW) or MI was controlled independently by adjustingthe ethylene conversion (% C₂) in the reactor via the catalyst flowrate. Finally, the polymer density was controlled by adjusting theethylene/1-octene weight ratio in the feed. See Tables below.Polymerization Conditions Exp 14 Cat. Feed Act. Feed Alkyl-Al Rt Temp.Press. Solvent C₂ Feed C₈ Feed # Cat Act (mg/hr) (mg/hr) (mmol/l) (min)(° C.) (bar) (kg/hr) (kg/hr) (kg/hr) a) A (F₅C₆)₄B⁻⁽¹⁾ 3.3 2.7 0.015 7.2190 85.8 5.5 1.16 0.53 b) A (F₇C₁₀)₄B⁻⁽²⁾ 5.2 5.8 0.015 7.0 196 85.8 5.71.17 0.54

[0083] Product Analysis Exp 14 C₂ Conv C₈ Conv Prod Rate Cat. Prod. MIMIR Density C₈ Incorp. M_(w) PDI # (%) (%) (kg/hr) (kgPE/mg Cat)(dg/min) (I21/12) (kg/m³) (wt %) (kg/mol) (M_(w)/M_(n)) a) 84 48 1.46440 0.84 39 .903 17 95 2.3 b) 85 45 1.47 280 0.96 42 909 16 89 2.2

1. A Group 4 organometallic compound comprising two ancillary monanionicligands, each of which independently may be substituted orunsubstituted, wherein the ligands are bonded by a covalent bridgecontaining a substituted single Group 14 atom, the substitution on saidGroup 14 atom comprising aryl groups at least one of which contains atleast one hydrocarbylsilyl substituent group.
 2. The compound of claim 1wherein said hydrocarbylsilyl substituent has the formulaR_(n)″SiR′_(3-n), where each R′ is independently a C₁-C₂₀ hydrocarbyl,hydrocarbylsilyl, hydrofluorocarbyl substitutent, R″ is a C₁-C₁o linkinggroup between Si and the aryl group, and n=0 or
 1. 3. The organometalliccompound of claim 2 wherein each R′ is a linear C₁-C₆ linear or branchedalkyl substituent.
 4. The organometallic compound of claim 3 whereinsaid catalyst compound is a hafnium organometallic compound and saidsubstituted Group 14 atom is a carbon atom.
 5. The organometalliccompound of claim 4 wherein said compound is a biscyclopentadienylhafnium organometallic compound having i) at least one unsubstitutedcyclopentadienyl or indenyl ligand, ii) one aromatic fused-ringsubstituted cyclopentadienyl ligand.
 6. The organometallic compound ofclaim 4 wherein said aromatic fused-ring substituted cyclopentadienylligand is a substituted or unsubstituted fluorenyl ligand.
 7. Theorganometallic compound of claim 6 wherein said unsubstitutedcyclopentadienyl ligand or aromatic fused-ring substitutedcyclopentadienyl ligand is an unsubstituted cyclopentadienyl ligand. 8.The organometallic compound of claim 7 wherein said hafnium compound isselected from the group consisting of di(p-trimethylsilyl-phenyl)methylene (cyclopentadienyl) (fluorenyl) hafnium dimethyl,di(p-trimethylsilyl-phenyl) methylene (cyclopentadienyl)(2,7-dimethyl-9-fluorenyl) hafnium dimethyl anddi(p-trimethylsilyl-phenyl) methylene (cyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl) hafnium dimethyl,di(p-triethylsilyl-phenyl) methylene (cyclopentadienyl) (fluorenyl)hafnium dimethyl, di(p-triethylsilyl-phenyl) methylene(cyclopentadienyl) (2,7-dimethyl-9-fluorenyl) hafnium dimethyl,di(p-triethylsilyl-phenyl) methylene (cyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl) hafnium dimethyl,(p-triethylsilyl-phenyl) (p-tert-butylphenyl) methylene(cyclopentadienyl) (fluorenyl) hafnium dimethyl,(p-triethylsilyl-phenyl)) (p-n-butylphenyl) methylene (cyclopentadienyl)(2,7-dimethyl-9-fluorenyl) hafnium dimethyl, (p-triethylsilyl-phenyl)(p-n-butylphenyl) methylene (cyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl) hafnium dimethyl, and(p-triethylsilyl-phenyl) (p-n-butylphenyl) methylene (cyclopentadienyl)(2,7-dimethyl-9-fluorenyl) hafnium dimethyl.
 9. A polymerization processfor ethylene copolymers having a density of about 0.850 to about 0.940comprising contacting, under solution polymerization conditions at areaction temperature at or above 60° C. to 225° C., ethylene and one ormore comonomers capable of insertion polymerization with a catalystcompound derived from the Group 4 organometallic compound of claims 1-7.10. The process of claim 9 wherein said catalyst compound is a hafniumorganometallic compound and said substituted Group 14 atom is a carbonatom.
 11. The process of claim 9 wherein said catalyst compound isderived by reacting with an activating cocatalyst compound.
 12. Theprocess of claim 11 wherein said cocatalyst compound comprises ahalogenated tetraaryl-substituted Group 13 anion.
 13. The process ofclaim 12 wherein the aryl substituent comprises at least one fusedpolycyclic aromatic ring.
 14. The process of claim 13 wherein saidhalogenated tetraaryl Group 13 anion is[tetrakis(perfluoro-naphthyl)borate].
 15. The process of any of claims12-14 wherein said cocatalyst compound additionally comprises anessentially cationic complex selected from substituted or unsubstitutedanilinium, ammonium, carbenium, silylium and metal cationic complexes.16. The process of any of claims 9-15 wherein said solutionpolymerization conditions are adiabatically conducted in a continuouspolymerization process.
 17. The process of claim 16 wherein the reactiontemperature is in a range of 160° C. to 250° C.
 18. The process of claim17 wherein said homogeneous polymerization conditions are conducted in acontinuous process at a pressure of at least 500 bar.
 19. The process ofany of claims 9-18 wherein said one or more comonomers capable ofinsertion polymerization are selected from the group consisting one ormore of C₃-C₈ α-olefins, C₅-C₁₅ diolefins, C₇-C₂₀ cyclic olefins anddiolefins, and C₇-C₂₀ vinyl aromatic monomers.
 20. The process of claim19 wherein said one or more comonomers capable of insertionpolymerization are selected from the group consisting of propylene,1-butene, 1-hexene, 1-octene, 2-ethylidene-5-norbomene, and2-vinyl-5-norbomene.
 21. The process of claim 9 wherein said Group 4organometallic compound comprises a monocyclopentadienyl,heteroatom-containing titanium compound.